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1.
Economies are instances of complex socio-technical systems that are shaped by the interactions of large numbers of individuals. The individual behavior and decision-making of consumer agents is determined by complex psychological dynamics that include their own assessment of present and future economic conditions as well as those of others, potentially leading to feedback loops that affect the macroscopic state of the economic system. We propose that the large-scale interactions of a nation''s citizens with its online resources can reveal the complex dynamics of their collective psychology, including their assessment of future system states. Here we introduce a behavioral index of Chinese Consumer Confidence (C3I) that computationally relates large-scale online search behavior recorded by Google Trends data to the macroscopic variable of consumer confidence. Our results indicate that such computational indices may reveal the components and complex dynamics of consumer psychology as a collective socio-economic phenomenon, potentially leading to improved and more refined economic forecasting. 相似文献
2.
I M Kooter N Moguilevsky A Bollen L A van der Veen C Otto H L Dekker R Wever 《The Journal of biological chemistry》1999,274(38):26794-26802
The heme group of myeloperoxidase is covalently linked via two ester bonds to the protein and a unique sulfonium ion linkage involving Met(243). Mutation of Met(243) into Thr, Gln, and Val, which are the corresponding residues of eosinophil peroxidase, lactoperoxidase, and thyroid peroxidase, respectively, and into Cys was performed. The Soret band in the optical absorbance spectrum in the oxidized mutants is now found at approximately 411 nm. Both the pyridine hemochrome spectra and resonance Raman spectra of the mutants are affected by the mutation. In the Met(243) mutants the affinity for chloride has decreased 100-fold. All mutants have lost their chlorination activity, except for the M243T mutant, which still has 15% activity left. By Fourier transform infared difference spectroscopy it was possible to specifically detect the (13)CD(3)-labeled methionyl sulfonium ion linkage. We conclude that the sulfonium ion linkage serves two roles. First, it serves as an electron-withdrawing substituent via its positive charge, and, second, together with its neighboring residue Glu(242), it appears to be responsible for the lower symmetry of the heme group and distortion from the planar conformation normally seen in heme-containing proteins. 相似文献
3.
4.
Alain Jacquet Vronique Daminet Michle Haumont Lida Garcia Sylvie Chaudoir Alex Bollen Ralph Biemans 《Protein expression and purification》1999,17(3):392
A 268-amino-acid-residue carboxy-terminal antigenic fragment of the Toxoplasma gondii rhoptry protein ROP2 (recROP2t, residues 196–464) was expressed in Escherichia coli. This recombinant fragment was produced at low concentration and in a highly insoluble form. By contrast, the level of recROP2t production was drastically greater when the same coding sequence was fused to the C-terminus of thioredoxin (TRX) or to the maltose-binding protein (MBP) gene. While both fusion proteins were found to be mainly insoluble, solubilization could be achieved without significant degradation. MBP was more efficient than TRX in increasing the recovery of soluble protein with more than 10% of total MBP–recROP2t being readily expressed in a soluble form. Moreover, the insoluble form of MBP–recROP2t could be correctly refolded with a recovery of more than 80%. Both forms of MBP–recROP2t were purified to homogeneity by amylose chromatography. In contrast, the refolding of TRX–recROP2t promoted aggregation of the protein, which was prevented by the use of zwitterionic detergent during the one-step purification by gel filtration. Subsequent proteolytic cleavages of purified TRX–recROP2t and of MBP–recROP2t led respectively to the complete degradation or to the truncation of the recROP2t moiety. However, recROP2t, despite the presence of the fusion partners, adopted a suitable conformation recognized by human serum-derived antibodies from T. gondii-seropositive individuals. Finally, both fusion proteins were able to induce specific humoral and cell-mediated immune response to the ROP2 fragment. Such fusions could represent an alternative to study the immunogenicity of T. gondii proteins which are difficult to produce because of insolubility and degradation. 相似文献
5.
K. L. M. Freeman A. Bollen F. J. F. Solofoniaina H. Andriamiarinoro I. Porton C. R. Birkinshaw 《Plant biosystems》2013,147(3):570-580
Using the example of Madagascar Fauna and Flora Group (MFG), we look at the factors which contribute to the successful maintenance of an international consortium dedicated to the conservation of Malagasy biodiversity. We discuss the philosophy, mission and set-up of the MFG and how, over its 25-year history, it has enabled the productive collaboration of its diverse international members to achieve the common goal of helping to protect Madagascar's unique biodiversity. We explore the benefits of pooling resources to fund a stable base of personnel and infrastructure to maximise the conservation impact of contributions from organisations that might not otherwise be able to fund viable independent programmes and consider the benefits that accrue to partners in the consortium. We highlight specific examples of plant conservation projects set up as a result of the productive working relationship between MFG and Missouri Botanical Garden to reinforce the argument that like-minded organisations working in successful partnership can far exceed the conservation capacity of individual institutions. 相似文献
6.
Ingeborg M. Kooter Brian P. Koehler Nicole Moguilevsky Alex Bollen R. Wever Michael K. Johnson 《Journal of biological inorganic chemistry》1999,4(6):684-691
The heme group of myeloperoxidase shows anomalous optical properties, and the enzyme possesses the unique ability to catalyze
the oxidation of chloride. However, the nature of the covalently bound heme macrocycle has been difficult to identify. In
this work, the electronic and magnetic properties of the heme groups in oxidized and reduced forms of wild-type and Met243Thr
mutant myeloperoxidase and wild-type lactoperoxidase have been investigated using variable-temperature (1.6–273 K) magnetic
circular dichroism (MCD) spectroscopy along with parallel optical absorption and electron paramagnetic resonance studies.
The results provide assessment of the spin state mixtures of the oxidized and reduced samples at ambient and liquid helium
temperatures and show that the anomalous MCD properties of myeloperoxidase, e.g. red-shifted and inverted signs for bands
in the high-spin ferric and low-spin ferrous forms compared to other heme peroxidases and heme proteins in general, are a
direct consequence of a novel electron-withdrawing sulfonium ion heme linkage involving Met243.
Received: 3 May 1999 / Accepted: 9 August 1999 相似文献
7.
M.C. Corchuelo A. Herzog L. Desmarez R. Lavallé A. Bollen 《Biochemical and biophysical research communications》1981,100(4):1497-1503
An mutant resistant to the peptide-like antibiotic negamycin carries a mutation, NEG40, which maps at minute 65 on the bacterial genome. Termination of protein synthesis, which is normally blocked by negamycin in wild type cellular extracts, continues with cellular extracts from the mutant in the presence of the drug; indeed, release of complete peptides from the polysomes still proceeds over a wide range of drug concentrations. The data suggest that the NEG40 mutation affects one of the components of the termination complex (ribosome or release factor). 相似文献
8.
I M Kooter N Moguilevsky A Bollen N M Sijtsema C Otto H L Dekker R Wever 《European journal of biochemistry》1999,262(1):211-217
Neurofilaments (NFs) are neuron-specific intermediate filaments, and are the major cytoskeletal component in large myelinated axons. Lysine-serine-proline (KSP) repeats in the tail domains of high molecular weight NF proteins (NF-M and NF-H) are extensively phosphorylated in vivo in the axon. This phosphorylation in the tail domain has been postulated to play an important role in mediating neuron-specific properties, including axonal caliber and conduction velocity. Recent studies have shown that the mitogen-activated protein kinases (extracellular signal-regulated kinases, Erk1 and Erk2) phosphorylate KSP motifs in peptide substrates derived from the NF-M and NF-H tail domains in vitro. However, it is not clear whether activation of the mitogen activated protein (MAP) kinase pathway is able to phosphorylate these domains in vivo. To answer this question, a constitutively active form of mitogen-activated Erk activating kinase (MEK1) was cotransfected with an NF-M expression construct into NIH 3T3 cells. The activated mutant, but not the dominant negative mutant, induced phosphorylation of NF-M. In addition, it was shown that epidermal growth factor, which induces the MAP kinase cascade in NIH 3T3 cells, also activated endogenous Erk1 and Erk2 and NF-M tail domain phosphorylation in the transfected cells. These results present direct evidence that in-vivo activation of Erk1 and Erk 2 is sufficient for NF-M tail domain phosphorylation in transfected cells. 相似文献
9.
Localized P1 mutagenesis was used to screen for conditionally lethal mutations in ribosomal protein genes. One such mutation, 2859mis, has been mapped inside the ribosomal protein gene cluster at 72 minutes on the Escherichia coli chromosome and cotransduces at 98% with rpsE (S5). The 2869mis mutation leads to thermosensitivity and impaired assembly in vivo of 50 S ribosomal particles at 42 °C. The strain carrying the mutation has an altered L24 ribosomal protein which at 42 °C shows weaker affinity for 23 S RNA than the wild-type protein. The mutational alteration involves a replacement of glycine by aspartic acid in protein L24 from the mutant. We conclude therefore that the 2859mis mutation affects the structural gene for protein L24 (rplX). 相似文献
10.